((n+1)/2)n

Date: 01/31/2002 at 05:52:53
From: Alan Naude
Subject: Proof of an equation
If you want to figure out the total of a series of numbers in order,
e.g.: 1+2+3+4+5+6+7+8+9 etc., you would use the formula below where
n is the final number of your series.
((n+1)/2)n
Why, and what is the proof of the formula?